Celestron CG-5 not moving on RA axis.

[Orion C8]

Hello everyone! Last August I got my first goto scope. An Celestron C8 with an CG-5 mount. The scope has been great, but the mount as always been slow when slewing to the left on the RA axis. And just this week it has completely stopped moving in that direction. I hope to figure out what the problem is, and maybe to fix it myself, but if all fails I'll just return it and get a new one.

I have an provided a video below demostrating what is happening.

http://www.youtube.com/watch?v=K3UP99_qIKs

Thanks.

[E621Keith]

Hi Welcome to SGL

I have not seen this problem before, but different speed in different direction may be caused by issues with balanced. Are you sure your mount is properly balanced?

I don't have a C8 so I don't know how many weights it needs, but my C6 uses one large weight and C925 usess 3.

Did you start your scope in the home position. If you didn't, is it possible the mount may be thinking it has hit the software slew limit and stop.

Was the time, date and location entered in the correct format?

[Orion C8]

Hi Welcome to SGL

I have not seen this problem before, but different speed in different direction may be caused by issues with balanced. Are you sure your mount is properly balanced?

I don't have a C8 so I don't know how many weights it needs, but my C6 uses one large weight and C925 usess 3.

Did you start your scope in the home position. If you didn't, is it possible the mount may be thinking it has hit the software slew limit and stop.

Was the time, date and location entered in the correct format?

Yes indeed it was balanced correctly with just one counter weight, which is all you need with an C8. And I am starting it in home position. The time, date, and location isnt a factor in this. This is an actual problem with the inner workings of the scope, and none of that has to do with it.

I did how ever send this over to reddit before you guys, and for what I was told is that Celestron tends to put to thick of grease on their mounts, thus can do this, and gets worse when it gets cold.

[lardy]

Have you tried slewing with no weight and scope on? ..... on the grease issue does the mount work in doors were it is warmer? and if the mount is under warranty DON'T touch it you will void the warranty

If it slews with nothing on then I would look at balance .... If it still does not move then motor problem?

Merry Xmas

Mark

[Orion C8]

s

Have you tried slewing with no weight and scope on? ..... on the grease issue does the mount work in doors were it is warmer? and if the mount is under warranty DON'T touch it you will void the warranty

If it slews with nothing on then I would look at balance .... If it still does not move then motor problem?

Merry Xmas

Mark

I just tried it without the scope and counter weight and it didnt stop, unlike before, but I realized that it completely stopping was actually caused by the home position, so my bad on that. But with or without the scope and the counter weight, it is still going really slow, and probably isnt good for gearing. Also, everything im talking about right now is inside.

I took another video to demonstrate whats going on now:

http://www.youtube.com/watch?v=1GU_4T6lDMI

Thanks for the help so far, and sorry for being a little unknowable.

[Chris Rowland]

From a listen to this my guess is that the worm is set a little close and is binding. The main ring will not be perfectly circular so it can be fine in one position but not in another. Has this had any tuning or adjustment? If not I'd get back to your dealer.

Normal operation only moves the scope through 180 degrees in the RA axis so it might be possible to avoid the tight area.

Chris

[Grotemobile]

It sounds like the mount, is not getting the full

voltage.It is very slow.There is something wrong

somewere.My CG-5 takes a C11, with all the

weights with no problems.Check that the voltage

going into the mount is 12 volt.If it is. i would

send it back.I would not try to sort it out, if it

is still under warranty.Try using another

power lead.It might be that.

Steve.

.

[Uranium235]

It should still be covered by its 12 month warranty, so you should be ok.

If it were beyond that, its a case of strip, clean, regrease and retune. I used to run mine at 13.5v to ensure smooth running.

Ive just looked at the video and that motor noise is a clear sign of the worm gear needing adjustment, or some sort of strip down. The pitch of the RA motor is all over the place, it should be of a constant tone and not rising/falling.

[cantharis]

I did how ever send this over to reddit before you guys, and for what I was told is that Celestron tends to put to thick of grease on their mounts, thus can do this, and gets worse when it gets cold.

My EQ5 (a clone of the CG5) is much smoother all round since I cleaned out the glue-like glop that Synta put in these mounts (heaven knows why) and replaced it with a Lithium grease - but I have a feeling that is not your problem.

[brantuk]

If the Dec moves ok and it's just the RA giving the problem - try loosening the RA setting circle by undoing the little screw above it. I'm just stabbing in the dark and eliminating possibilities but it might make a difference.

[billhinge]

I fiddled many times with my CG5 including changing the tension on the gears and I've had a similar problems depending on the tension, Dec turns one way, slips the other, my money is on Chris's explanation

If so I don't think you can fix it without opening which would invalidate the guarantee so I would send it back - it is an easy but fiddly fix if this is the problem and you know what you are doing (the RA is much more fiddly than Dec)

[M4lcs67]

I own a CG5 which I use with my C 9.25 ota. While I don't really know what the problem is I read what Keith said about the C9.25 needing 3 counterweights.

That actually answers another question for me, as on all the Celestron blurb supplied with my scope it says that the C9.25 ota uses 2 counterweights which were in the mount/tripod box, but when it was delivered by Fedex from FLO an additional counterweight was supplied in a separate box. Thus far I haven't used the third counterweight. Does this mean that the third one should be used????

Apologies Orion C8 for jumping in on this post, but I was looking through it and read what E621Keith put, so I though I would ask the question.

[billhinge]

I received 3 counterweights with my C11 and I have them at the very edge of the counterweight bar and it's really obvious that it needs 3, otherwise the tube wont balance .

So I guess if you aren't noticing a need for 3 then you don't need them. The balance depends on the weight and distance from the mounts pivot point which the OTA and weights turn around

so you could "possibly" have 3 weights and keep them close to the pivot of the mount, or you could have 2 and position them at the very end of the bar, the bar is acting as a spring so 3 close in should theoretically have less vibration than 2 at the end providing 3 doesn't overbalance things